Neuroanatomic differences of the brain in males and females

Abstract

Gender distribution is an important factor in patient cohorts which may influence the results acquired in studies on pathogenesis and treatment of neuropsychiatric disorders. In all age groups, the mean brain volume is approximately 8–15% larger in males than in females, so the absolute volumes of almost all neuronal and white matter brain structures are larger in males. Several studies showed that body size and brain volumes may influence the results of neuroanatomical studies. In addition, brain maturation rate is faster in females than in males which should be considered as another important contributor to possible inconsistencies in the results of studies of gender effects on neuroanatomy, particularly in cohorts of young patients. Taking those circumstances into account, the most consistent findings in this field demonstrated larger amygdala volume in males in comparison with females, which was applicable to both paediatric and adult populations. Data on gender differences in neuroanatomy of visual and auditory cortical areas seem to be reasonable. Larger relative volumes of limbic and paralimbic cortex in females in comparison with males were consistently found in a range of studies as well. Overall, global and regional hemisphere asymmetry values are more pronounced in males in comparison with females.